3 - Earth History and Implications for Vertebrate Evolution

A comprehensive set of flashcards summarizing key concepts from the zoology lecture on Earth history and vertebrate evolution.

What is the Palaeozoic era known for in relation to vertebrates?

Known for the emergence of vertebrates, particularly jawless fishes and the evolution of jaws.

What significant landmass formed around 300 mya?

Pangaea, a single landmass that contained all current continents.

What was a major effect of the breaking apart of Pangaea?

Isolation of vertebrate lineages allowing for independent evolution.

What is the Great American Biotic Interchange?

The event that occurred around 3 mya when North and South America were connected, allowing terrestrial vertebrates to migrate.

Which oceanic circulation drives the Gulf Stream?

The Atlantic Meridional Overturning Circulation (AMOC).

What happens to the AMOC as polar glaciers melt?

The circulation weakens due to the addition of lighter fresh water.

What is the significance of eustatic sea level changes?

They affect the amount of land available for organisms and separate previously connected areas.

What climatic and geological change resulted from rising eustatic sea levels?

Rising eustatic sea levels caused a warmer, more stable global climate because shallow seas absorbed and distributed heat across the planet. Flooding of continental regions, creating epicontinental or epeiric seaways.

What does the term 'epicontinental' mean?

Referring to shallow seas lying on top of continental shelves.

What does the Cretaceous signify in geological history?

A period marked by the extensive division of North America due to the Western Interior Seaway.

What significant event defines the transition between the Mesozoic and Cenozoic eras?

The Cretaceous-Palaeogene (K-Pg) extinction event.

What were the dominant vertebrates during the Mesozoic era?

Sauropsida, which includes reptiles, birds, and dinosaurs.

What innovation was seen in marine life during the Mesozoic?

The appearance of more evolved teleost fishes.

What important adaptations were observed in vertebrates during the End-Permian extinction?

A drastic reduction in diversity, where about 95% of marine organisms died out.

What geological period followed the Palaeozoic era?

The Mesozoic era.

What is the main characteristic of the climate during the Mesozoic?

A warm climate with little temperature variation between equator and poles.

What type of fish first appeared during the Devonian period?

Jawed fishes, known as placoderms.

How did terrestrial vertebrates arise in the Palaeozoic?

From aquatic ancestors migrating to land.

What major event occurred about 450 mya?

The onset of major glaciation leading to cooler climates.

What factor greatly influenced vertebrate evolution throughout geological history?

The movement of continental landmasses.

What were the two major lineages of jawed vertebrates that flourished in the Devonian?

Acanthodians (spiny sharks) and Chondrichthyes (cartilaginous fishes).

What term describes the major extinction event at the end of the Permian?

The Permian–Triassic extinction, or Great Dying, occurred about 252 million years ago when massive volcanic eruptions in the Siberian Traps caused global warming, ocean acidification, and oxygen loss, wiping out over 90% of marine species and 70% of land species.

What were the earliest tetrapods?

Amphibious vertebrates that evolved in the late Palaeozoic.

What significant geological change occurred during the Jurassic period?

The separation of Pangaea into Laurasia and Gondwana.

What mammal ancestor groups survived after the Permian extinction?

Synapsida, which led to modern mammals.

What important feature characterized the climate at the end of the Cretaceous?

A cool, stable, greenhouse climate.

What are epicontinental seas?

Shallow seas that cover continental shelves during high sea levels.

What is the Great American Schism?

The blocking of connection between Atlantic and Pacific oceans around 3 mya.

What does the term 'terrestrial vertebrates' refer to?

Land-dwelling vertebrate species.

What major evolutionary innovation occurred during the Devonian?

The evolution of jaws in vertebrates.

What is significant about the Eocene epoch in relation to modern fauna?

By the Eocene, most modern mammal and teleost fish families were present.

What is a notable feature of the climate throughout the Cenozoic era?

A great variation in climate, with the formation of ice caps.

How did the geography of the earth influence vertebrate evolution?

Fragmented landmasses led to isolation and diversification of lineages.

What was the impact of the disappearance of the Western Interior Seaway?

Significant climate changes at the end of the Cretaceous.

What did increased calcium levels from terrestrial plants lead to in the ocean?

Formation of marine carbonates and decreased atmospheric CO2.

What is the role of orogenesis in the Cenozoic?

Creation of mountain ranges that acted as barriers and influenced climates.

What did the Cenozoic era signify for mammals?

The Age of Mammals, where mammals diversified to fill various ecological niches.

What is a defining feature of the Late Cenozoic geological changes?

The formation of modern continents and major mountain ranges along with global cooling and the onset of repeated ice ages.

What vertebrate group includes modern birds?

Archosaurs, which are derived from the ancestors of dinosaurs.

What evolution occurred due to climatic and environmental shifts during the Cenozoic?

Adaptations in mammals to fit into various climatic niches.

What are the names of the two major freshwater fish lineages that evolved during the Mesozoic?

Actinopterygii (ray-finned fishes) and Sarcopterygii (lobe-finned fishes).

What is the significance of the Miocene epoch in relation to continental connection?

The formation of a land connection between Africa and Eurasia.

What characterized vertebrate diversity at the beginning of the Cenozoic?

The presence of mammals diversifying to fill ecological roles left by dinosaurs.

Teleost

Modern bony fish in Actinopterygii with movable jaws, a symmetrical tail, light scales, and a swim bladder for buoyancy.